Simpson 4200 PSI Gas Pressure Washer, 4.0 GPM Commercial Power Washer, Cold Water, Honda GX390 Engine, 50' Hose, Aluminum Series, 49-State Compliant (ALH4240)

I read a LOT of reviews here on Amazon and other online resources before deciding to make such a sizable investment in this 4200 PSI/4.0 GPM machine. This is not my first pressure washer, but my third actually. Each time I upgraded in both PSI and gallons per minute. This is my first pressure washer that is categorized as commercial use. Having finally taken the time to put this machine to the test, I can honestly say this thing has more than enough power to satisfy the average homeowner or DIY’er. As I said in the title: this thing is a beast! Mine arrived complete and undamaged. Other reviewers reported scratches and dents but that was not my experience at all. Assembly was quick and easy. My shipment contained a quart of Amsoil synthetic 10W-30 for the engine crankcase but I have seen other reviewers that got their oil in a plastic pouch. Once assembled, the crankcase filled with the supplied oil, and the fuel tank filled 1/2 way, I hooked up the garden hose and bled the air out for 30+ seconds as recommended. Set the throttle to half-way and closed the choke and gave the starter a quick pull and it fired right up on the first attempt. After allowing the engine to run at partial throttle with the trigger open to keep the water flowing and the pump cooled for a few minutes, I increased the engine speed to approximately 3/4 and started cleaning the concrete patio as my first project with this unit. The pressure even at less than wide open on the Honda GX390 was more than enough to get the accumulated grime blasted off effortlessly. Next up, I connected my 15” surface cleaner which really sped up the process. The 4240 pressure and water flow are a perfect match for the Karcher 15” surface cleaner. With all of the positive attributes of this machine, there is one thing that I feel is a negative: the hose. It’s more than long enough for most jobs but the stiffness makes moving around with it a real challenge. Given the higher than average PSI capabilities of the ALH-4240 it’s not surprising that the pressure hose is more on the stiff side, but as others have commented, it would be a good idea to upgrade to a better hose. Honestly, at this price point, a better quality hose should come with it. Overall, the ALH-4240 is a great pressure washer that has all of the power that the average person could want for DIY use. The high PSI and GPM make short work out of even the toughest cleaning projects. Time will tell if it lives up to the Simpson advertised claims of dependability and reliability.

Simpson did a fantastic job in their design of the aluminum model (ALH4240) of the 4200 PSI pressure washer. The weight difference is quite amazing. The listing does not mention, and Amazon's AI states that the engine is not aluminum. However, I can say with certainty that the Honda engine block is in fact aluminum. My only complaints are packaging and delivery. Simpson could do a much better job of securing the PW and accessories in the box. The unit was loose in the box with no packing. Instead, when Amazon delivered it (Upside down), the main unit and the accessories were all just sitting in the box loosely. Because of this, and the fact that it was dropped off upside down, the unit was sitting awkwardly on the detached aluminum handle, crushing one of the ends. I reached out to Simpson, where they very quickly took care of me by sending a new handle. It should be here any day now.

This review is for the Simpson ALH4240 4200 PSI pressure washer. I replaced a similarly powered washer with this unit. The unit arrived with no apparent shipping damage and all appeared new. The “issues”, starting with least severe first. 1. The nut nearest one of the tires, threading through a bolt to the engine platform was not adequately tightened, and the nut fell off during the first usage session. Luckily I noticed it on the ground. 2. The aluminum handle bar (near the “dashboard”) had several burrs and nicks, which need to be buffed down to avoid scratches / cuts / etc while moving the unit. 3. It seems the included hose is unsuitable, and Simpson should provide a suitable replacement. It’s extremely rigid due to the metal layer running the length of the hose. The biggest issue with this is a very large amount of mechanical vibration is transferred from the motor/pump directly to the end-user/operator. IT’S PAINFUL TO EVEN USE THIS FOR MORE THAN A FEW MINUTES. Repetitive stress injury in the wrist/arm seems a real potential, on top of reduced productivity. The amount of vibration is obvious if you put your foot lightly on the hose. “Fighting” the hose while moving around is an issue too. You need to test this and have a mechanical engineer address the issue.

This is a solid unit, very happy with this purchase. Well worth the price. I had a different brand which was an electric model previously but it was only good for small projects. This Simpson 4200 PSI gas pressure washer is a game changer and it has cut my cleaning time down by more than half. It's also easy to use and start. I highly recommend it to anyone looking for something more commercial-grade and more powerful than just a high-end consumer power washer. This power washer is amazing.

Works great and a lot of power. Can't beat the Honda and Cat combo. Quick to put together and it arrived in great shape.

This Simpson pressure washer is top quality. The Honda GX390 engine coupled with the CAT pump can handle any job to include a 20" surface cleaner. My only reason for the 3 star review is the packaging and delivery. It boggles my mind that Amazon would actually package an expensive, heavy, bulky item with no support other than a cardboard box. Further, the unit was left on my porch actually upside down. Beware! ... this item clearly states "Non Returnable" so thank goodness it wasn't damaged.

Of course the Honda engine is very well built as is the aluminum frame. All Honda motors have a weird oil level check they should throw away the dipstick you just fill the oil to the bottom of the threads it's less confusing. Strong CAT pump wish I had a better place to coil the hose as it's super stiff but obviously well built

Love this machine! It gives so much pressure and works perfect with a 16” surface cleaner! Reliable Honda gx390 with a CAT pump is the best combo for only 1500$